Treadstone Associates
Case File № 404 · Renewals & Switches

The port expired while the closing slipped

re-qualifying fresh in Saguenay

A Saguenay family's lender agreed to port their 3.89% rate onto a new purchase, but the port carried a fixed commitment window and the new home's closing slipped past it. Losing the port — not any problem with the file — meant requalifying fresh at 4.95%, $150 a month more, forever.

QuebecUninsured · PurchaseFiled August 9, 20265 min read
3.89%→4.95%

the rate lost when the port's commitment window lapsed

$150/mo

extra cost, forever, purely from the closing date slipping

32.9%

TDS at the qualifying rate the fresh requalification required

Anonymized illustration. The borrowers, dollar figures, and rates in this file are an illustrative composite — no real client is identifiable, and any rate shown is illustrative, not a quote. The rules are real: every regulatory figure is cited to its source in the Sources section, and the math computes exactly as shown.

№ 01

The client

A family in Saguenay, Quebec sold one home and bought another, needing a new $255,000 mortgage and wanting to port their existing 3.89% rate across rather than lose it to a fresh, higher one.

New mortgage required

$255,000

Saguenay purchase, 25% equity, uninsured

Rate they wanted to port

3.89%

Their existing, below-market rate

Combined income

$7,400/month

Both salaried

Other debt

$280/mo car loan

Unchanged throughout

What happened

The port's commitment window lapsed

The new home's closing slipped past it

№ 02

The problem

A ported rate is not an unconditional promise — it's a commitment good for a specific window between discharging the old mortgage and closing the new purchase. This family's port carried exactly that kind of window, and the new home's closing slipped past it before the sale of the old home had even finished, for reasons that had nothing to do with the mortgage file itself.

Why the port expired

  • The lender's port commitment ran for a fixed number of days between the old mortgage's discharge and the new purchase's closing
  • The new home's closing date slipped past that window — a scheduling delay on the purchase side, not a lender or underwriting problem
  • Once the window lapsed, the ported 3.89% rate was gone; there was no lender-side exception or extension available

Nothing about the file itself was ever in question — the family qualified easily either way. The entire cost of this story is the difference between a rate they had already secured and a rate they had to requalify for fresh, purely because of a calendar.

№ 03

The numbers

The mortgage amount never changed. Only the rate did — and with it, the qualifying rate the file had to be tested against.

What the lapsed port actually costAmount
New mortgage amount required$255,000
Payment if the port had gone through (3.89%)$1,326/mo
Payment at the current posted rate (4.95%)$1,476/mo
Extra cost, every month, forever$150
Total debt serviceIf the port had gone throughRequalified fresh
Mortgage payment$1,326 (3.89%)$1,476 (4.95%, actual)
Property tax and heat$375$375
Car loan$280$280
Total debt service26.8%28.8%

At the qualifying rate the lender actually underwrote to — 6.95%, the greater of 4.95% plus 2% or the 5.25% floor — the stress-tested payment comes to $1,778/mo, for a TDS of 32.9%. The file was never close to a decline at any of these figures; the entire story is what a missed window costs against Canadian mortgage renewal statistics showing how often a rate simply carries forward without incident.

№ 04

The solution

A courtier hypothécaire licensed under Quebec's Act respecting the distribution of financial products and services stopped the family from chasing a remedy that didn't exist and moved immediately to protect the closing itself.

First, confirmed in writing that the port window had actually lapsed. Getting a clear answer from the lender, rather than an ambiguous one, stopped the family from waiting on an exception that was never coming while the closing date approached.

Second, moved immediately to fully requalify the purchase at the current posted rate. Since the port was gone regardless, the priority shifted to protecting the closing date itself rather than continuing to negotiate over a rate that was no longer available.

Third, locked the fresh rate the moment requalification was confirmed. With the port off the table, there was no reason to leave the replacement rate floating while further delays risked pushing the closing again.

Written confirmation from the lender that the port window had lapsed
Updated mortgage application for a fresh purchase, not a port
Two years of income documentation for both borrowers
New rate lock confirmation at the current posted rate
Revised closing timeline confirmed with both real estate lawyers
№ 05

The outcome

The purchase funded at 4.95%, uninsured, after a full fresh requalification. Total debt service came to 28.8% against the payment actually being paid, and 32.9% at the stress-tested qualifying rate the lender underwrote to — comfortably clear of any ceiling either way, but $150 a month more than the ported rate would have cost, for as long as the mortgage runs.

Because this file is uninsured (25% down), CMHC's ratio maximums don't apply directly; the TDS figures here measure the cost of the lapsed port, not a regulatory pass/fail line.

№ 06

What to take from this file

  • 01A ported rate is a commitment with a window, not an unconditional guarantee. The window runs on the lender's terms, tied to the discharge and the new closing, and a purchase-side delay can burn through it without anyone at the mortgage file doing anything wrong.
  • 02Once a port window lapses, there is typically no lender-side remedy. Confirm the lapse in writing quickly rather than losing time hoping for an exception.
  • 03Protect the closing date once the port is gone. Continuing to negotiate over a rate that no longer exists risks the purchase itself; requalifying fresh, quickly, is usually the better use of the remaining time.
  • 04A rate loss can cost more than a ratio failure ever would. This file was never close to a decline at any rate tested — the entire cost here is $150 a month, forever, purely from timing.
  • 05Calendar the port window the day the commitment is made, not the week of the new closing. A window tracked from day one leaves room to react if a purchase-side delay threatens it.

Sources

Every regulatory figure in this file traces to one of these primary sources. Client details and anything that varies by lender are illustrative, as flagged below.

Illustrative in this file — lender-specific, not rules:

  • 3.89% / 4.95% rates — rates move daily; neither is a quote.
  • the port commitment window itself — each lender sets its own port policy and window length; there is no published universal rule.
  • the TDS figures — this file is uninsured (25% down), so there is no CMHC ratio ceiling -- the numbers are informational.

Authority & provenance

How this case file was built

We publish the origin, the verification method and the reviewer for every case file, so you can judge how far to trust it before you rely on it with a client.

Where it comes from

Derived from files handled by Treadstone’s fulfillment desk and from scenarios contributed by partner brokerages. Names, employers, exact amounts and dates are changed so no client or file is identifiable.

Provenance: Composite — a pattern seen repeatedly on fulfilled files, not a single transaction.

What is verified

Every regulatory figure traces to a primary source listed above and was checked against it on the date shown. The arithmetic is recomputed by machine on every rebuild.

Anything that varies by lender is labelled illustrative rather than stated as a rule.

Who reviewed it

Reviewed for Canadian regulatory accuracy before publication, and re-checked whenever a cited rule changes.

Reviewed by: Nicholas Parson, Treadstone Associates — reviews every case file before publication.

First published 9 August 2026Rules last verified 9 August 2026Next scheduled review 9 February 2027

This case file is professional reference material for licensed mortgage professionals. It is not advice to a borrower, and it is not a lender commitment. Insurer rules, qualifying rates and provincial taxes change — confirm the current position with the insurer, regulator or lender before you rely on any figure here in a live file.

Treadstone fulfillment

Files like this are daily work for our desk.

Document collection, ratio math under multiple treatments, lender placement notes, and submission-ready packaging — for Canadian mortgage brokers who would rather be in front of clients.